Causes of ischemic diseases of an organ can be roughly divided into hemodynamic failure and function failure of the organ itself. For the situations where the cause is hemodynamic failure, it is in demand to provide an evaluation index that can suggest a treatment method in a non-invasive manner and a technique that can be used in diagnosis processes.
For example, stenosis, which is an example of hemodynamic failure in coronary arteries, is a serious pathological issue that may lead to an ischemic heart disease. Ischemic heart diseases require to determine whether a drug treatment should be performed or a stent treatment should be performed, or the like. As a diagnosis method for evaluating hematogenous ischemia of coronary arteries, a recommended method in recent years has been a method by which a Fractional Flow Reserve (FFR) value is measured while using a wire guide, by performing a coronary angiography (CAG) examination that employs a catheter.
In this situation, for example, there is a possibility that the need to perform the catheter surgery may be eliminated, if it is possible to evaluate homogenous ischemia of coronary arteries, by using an X-ray Computed Tomography image (hereinafter, simply “CT image”), a Magnetic Resonance Angiography (MRA) image, or an ultrasound image of the heart.